Explaining the Ratings
Last week’s column on the local ratings brought in a couple inquiries that I think are worth covering. The first has to do with what ratings truly measure.
“Read your article in the Pasadena Star News today. I now realize I don’t understand the translation of the rating to real numbers.
“I had always assumed from TV ratings in the Times that a 7.1 rating equaled 7,100,000 viewers. Your numbers for radio I don’t think translate to millions. Please help me to understand.” — Terry Smith
Actually Terry has it down perfectly, at least in concept. There are a few differences though.
The TV ratings are basically the same as radio, except that radio counts actual people — locally — while television counts whole households — nationally.
The rating printed last week for radio is a percentage of listeners aged 6 and over. A share of 7.1 in radio, then, with a population of 11,419,500 (Los Angeles Metro of people aged 6 and over) would be .071 x 11,419,500 or 810,784.5 people aged 6 and over tuned in on average during the ratings period. Those ratings also reflect the entire broadcast day even though you can, like television, break down the day into smaller parts.
The details can also change depending on if you are looking at total listeners or subsets; if you split the rating into demographics (men aged 25-35 for example) the available population will be a subset of the 11,419,500. Further, radio ratings are not calculated nationally (not even syndicated shows) so the total number will be less than television ratings calculations.
On television the rating is calculated the same way except that they use households rather than individual people, and they are national rather than local. The 7.1 share equating to 7,100,000 households is from old data assuming 100,000,000 households with televisions in the house in the United States; it is now 115,600,000, so the 7.1 share now translates to 8,207,600 households. Like radio, though, it is a percentage of available households (vs. actual people in radio) tuned to a show.
The second letter had to do with ratings breakdowns.
“I read your column each week and I find the ratings most interesting. This week you added something extra, the Handel 4.2 vs. the Conway 4.5 rating. Could you sometime do a column comparing each show from 6 a.m. to 10 p.m. on the am talkers?” — Maurice Sutton
That’s a little tricky, because Nielsen (and it’s predecessor Arbitron) don’t release detailed ratings to the public or the press. All we get are the generic “6 plus” numbers, referring to the overall audience measured of radio listeners aged 6 and older during the entire broadcast day of 6 a.m. and 12 midnight.
And the list we get isn’t even the complete list, as stations that don’t subscribe to Nielsen in the area rated don’t get mentioned even though they are on the list that stations receive, and I am not allowed to mention non-subscribing stations. So when you see different breakouts, it is usually due to a station “secretly” sending me the data.
There’s also the problem of way too much detail. There are a multitude of demographics, time slots, and even ways of looking at ratings that can make the most ardent radio geek get blurry-eyed.
That being said, I am going to see if Nielsen would allow more detail to be published here. In the meantime, I can say that of the AM talkers you mentioned, KFI dominates in all day-parts by a wide margin. Nielsen won’t let me mention specific numbers — yet at least — but perhaps I can give them sometime described as an algebra problem.